init: seed content from candidature + mvp docs

content/docs-mvp/DIAGRAMS.md

@@ -0,0 +1,70 @@
+# Diagrams (Mermaid) — NowYouSea
+
+## Station — Wiring / Connections
+
+```mermaid
+flowchart LR
+  subgraph Sea[Sea / Underwater]
+    H3x[Aquarian H3x Hydrophone\nXLR output]
+    MS[MS5837-30BA\nPressure+Temp]
+    Cond[Conductivity probe\nTBD]
+  end
+
+  subgraph Station[NowYouSea Station]
+    XLR20[XLR cable 20m\n(shielded)]
+    Rubix[Roland Rubix 22\nUSB Audio Interface]
+    Pi[Raspberry Pi 4\n(Compute)]
+
+    Router[GL.iNet Puli GL-XE300\n4G Router (OpenWrt)\n+ own battery]
+
+    Daisy[dAISy AIS receiver\n(USB)]
+    AISA[AIS Antenna\n(VHF 156–162 MHz)\nRG58 coax 3m]
+
+    MPPT[MPPT Solar Charge Controller]
+    Panel[Solar panel 100W]
+    Batt[AGM 12V 60Ah\nCar battery]
+
+    Matek[Matek BEC12S PRO\n9–55V -> 5V (5A)]
+    DC12[12V distribution\n(fuses/switches TBD)]
+  end
+
+  %% Audio
+  H3x -- XLR --> XLR20 --> Rubix
+  Rubix -- USB --> Pi
+
+  %% Network
+  Pi -- Ethernet/Wi‑Fi --> Router -- 4G --> Cloud[(Backend / Cloud)]
+
+  %% AIS
+  AISA --> Daisy -->|USB| Pi
+
+  %% Sensors (TBD)
+  MS -. I2C / SPI (TBD) .-> Pi
+  Cond -. (TBD) .-> Pi
+
+  %% Power
+  Panel --> MPPT --> Batt --> DC12
+  DC12 --> Matek --> Pi
+  DC12 --> Rubix
+
+  %% Router is external power domain
+  Router -. self powered .- Router
+```
+
+## Data Flow (high-level)
+
+```mermaid
+flowchart TD
+  H[Hydrophone H3x] -->|Analog audio (XLR)| A[Rubix 22]
+  A -->|USB audio| Pi[Pi 4]
+
+  Pi -->|Record| S[(Local storage)]
+  Pi -->|Preprocess\n(filter/compress/events)| P[Edge processing]
+  P -->|Upload\nraw/clips/features| R[GL-XE300]
+  R -->|4G| API[Ingest API]
+  API --> DB[(Storage / DB)]
+  DB --> Dash[Dashboard / Alerts]
+
+  AIS[AIS dAISy] -->|NMEA (AIS messages)| Pi
+  Pi -->|Health metrics| R
+```